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Protective environmental factors for neuromyelitis optica.

 

Neurology. 2014 Nov 18;83(21):1923-9. doi: 10.1212/WNL.0000000000001001. Epub 2014 Oct 22.
Graves J1, Grandhe S2, Weinfurtner K2, Krupp L2, Belman A2, Chitnis T2, Ness J2, Weinstock-Guttman B2, Gorman M2, Patterson M2, Rodriguez M2, Lotze T2, Aaen G2, Mowry EM2, Rose JW2, Simmons T2, Casper TC2, James J2, Waubant E2; US Network of Pediatric Multiple Sclerosis Centers.

Abstract

OBJECTIVE:

To determine whether early environmental factors, such as cesarean delivery, breastfeeding, and exposure to smoking or herpes viruses, are associated with neuromyelitis optica (NMO) risk in children.

METHODS:

This is a case-control study of pediatric NMO, multiple sclerosis (MS), and healthy subjects. Early-life exposures were obtained by standardized questionnaire. Epstein-Barr virus, cytomegalovirus, and herpes simplex virus 1 antibody responses were determined by ELISA. Multivariate logistic regression models were used to adjust for age at sampling, sex, race, and ethnicity.

RESULTS:

Early-life exposures were obtained from 36 pediatric subjects with NMO, 491 with MS, and 224 healthy controls. Daycare (odds ratio [OR] 0.33, 95% confidence interval [CI] 0.14, 0.78; p < 0.01) and breastfeeding (OR 0.42, 95% CI 0.18, 0.99; p = 0.05) were associated with lower odds of having NMO compared with healthy subjects. Cesarean delivery tended to be associated with 2-fold-higher odds of NMO compared with having MS/clinically isolated syndrome (OR 1.98, 95% CI 0.88, 4.59; p = 0.12) or with being healthy (OR 1.95, 95% CI 0.81, 4.71; p = 0.14). Sera and DNA were available for 31 subjects with NMO, 189 with MS, and 94 healthy controls. Epstein-Barr virus, herpes simplex virus 1, cytomegalovirus exposure, and being HLA-DRB1*15 positive were not associated with odds of having NMO compared with healthy subjects.

CONCLUSIONS:

Exposure to other young children may be an early protective factor against the development of NMO, as previously reported for MS, consistent with the hypothesis that infections contribute to disease risk modification. Unlike MS, pediatric NMO does not appear to be associated with exposures to common herpes viruses.

© 2014 American Academy of Neurology.

PMID:
25339213
PMCID:
PMC4248458
DOI:
10.1212/WNL.0000000000001001